Art of puddling iron.



r Prion,

ROBERT A. CARTER, OF PITTSBURG, PENNSYLVANIA.

ART oF PUDLING IRON.

SPECIFICATION forming part of Letters Patent No. 701,294, dated June 3, 1902.

Application filed March 13, 1901I Serial No. 51,006. (No specimens.)

To aZZ whom it may concern.-

Be it known that I, ROBERT A. CARTER, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvements in the Art of Puddling Iron, of which improvements the following is a specification.

The invention described herein relates to certain improvements in the process of manufacturing wrought-iron, and has for its object a thorough removal or elimination of the phosphorus and impurities from the metal during the puddling operation.

The invention is hereinafter more fully described and claimed.

In the practice of my invention a bottom is formed on the hearth with cinder, as is the usual practice. Over this bottom and on the sides of the hearth ore is next spread and subjected to a sufficient heat to reduce it to a molten condition. This molten ore is then allowed to cool and harden. In the puddling operation this ore bottom will serve to prevent any impurities from the cinder bottom coming in contact with the metal to be treated. After the formation of this ore bottom finelydivided ore is spread over the ore bottom and the pig metal charged thereon. The amount of ore applied at this time is equal or approximately equal to five per cent. of the charge of pig metal; but these proportions may be varied within wide limits. After the pig metal has been charged it is melted and brought to a boiling temperature, as is the usual practice, such condition or temperature being shown by the sparks given ofi from the surface of the boiling metal. As soon as the metal becomes liquid the puddler will commence the stirring and agitation thereof, so as to effect a mixture of the molten metal with the ore on the bottom. As soon as the metal comes to a boil an additional quantity of ore equal to about five per cent. of the charge is added from time to time in small quantities, the stirring and agitation being continued during the addition of this ore and until the metal comes to nature.

In lieu of placing ore upon the ore bottom previous to charging the pig metal the Whole quantity of ore may be added to the bath gradually and in small quantities and after the metal has commenced to boil. By the addition of the ore, which should be low in phosphorus and sulfur, a dephosphorization, desulfurization, and decarburization of the pig metal is effected and that Without the addition of any impurities, such as are incident in the use of scale, cinder, lime, &c., as has been the practice heretofore. After the metal has come to nature and been thoroughly dephosphorized, desulfurized, and also decarburized to the desired extent the metal is balled, as is the usual practice.

After the cinder has become thin and fluid by reason of the high temperature and the addition of ore and been separated from the metal by the stirring thereof it can be re moved to any desired extent by tapping or bleeding either from the top or from the bot tom of the charge, as is Well known in the art.

In addition to its purifying action the addition of the ore to the molten bath retards the reduction of the molten metal to nature,

thereby insuring greater working or stirring of the meta1,as such working must be continuous until the metal comes to nature and is balled. By reason of this prolonged stirring a more thorough separation of cinder can be effected.

I claim herein as my invention- 1. As an improvement in the art of puddling iron,the method herein described,which oonsistsin forming an ore lining for the bottom of the hearth, charging the metal to be treated on the hearth, melting boiling and stirring the metal adding ore to the charge during the boiling and stirring and finally balling the charge, substantially as set forth.

2. As an improvement in the art of puddlingiron,the method herein described,which consists in forming an ore lining for the bottom of the hearth, spreading ore on such lining, charging the metal to be treated onto the ore, melting boiling and stirring the metal adding ore gradually to the molten metal and finally balling the charge, substantially as set forth.

. 3. As an improvement in the art of puddlin iron the method herein describcdmhich consists in forming an ore lining for the bot- In testimony whereof I have hereunto set tom of the hearth, charging the metal to be my hand. treated, melting boiling and stirring the metal ROBERT A CARTER adding ore in small quantities and. from time 5 to time after the metal has commenced to boil Witnesses:

and finally balling the charge, substantially DARWIN S. WoLooTT, as set forth. H. M. CoRWIN. 

